Joshua enlisted at age 18 in Company A, 4th Michigan Cavalry on February 6, 1864 at Dryden, Michigan. He joined the regiment at Nashville, Tennessee, on February 28, 1864. He assisted in the capture of Jefferson Davis and was selected as one of the few men to escort the captured Confederate States president to Washington. He was discharged at Edgefield, Tennessee, on August 15, 1865.